scholarly journals Contact angle and adsorption energies of nanoparticles at the air–liquid interface determined by neutron reflectivity and molecular dynamics

Nanoscale ◽  
2015 ◽  
Vol 7 (13) ◽  
pp. 5665-5673 ◽  
Author(s):  
Javier Reguera ◽  
Evgeniy Ponomarev ◽  
Thomas Geue ◽  
Francesco Stellacci ◽  
Fernando Bresme ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Contact Angle ◽  
Contact Angles ◽  
Liquid Interface ◽  
Neutron Reflectivity ◽  
New Approach ◽  
Adsorption Energies ◽  
Air Liquid Interface

A new approach, based on in situ neutron reflectivity and molecular dynamics has been developed for calculating contact angles of nanoparticles at interfaces.

scholarly journals Molecular Dynamics Simulation of Wetting Behavior: Contact Angle Dependency on Water Potential Models

2021 ◽  
Vol 1 (1) ◽  
pp. 10
Author(s):  
Lukman Hakim ◽  
Irsandi Dwi Oka Kurniawan ◽  
Ellya Indahyanti ◽  
Irwansyah Putra Pradana
Keyword(s):  
Molecular Dynamics ◽  
Contact Angle ◽  
Liquid Droplet ◽  
Center Of Mass ◽  
Contact Angles ◽  
Surface Wettability ◽  
Dynamics Simulation ◽  
Potential Models ◽  
Surface Hydrophilicity ◽  
Dynamics Simulations

The underlying principle of surface wettability has obtained great attentions for the development of novel functional surfaces. Molecular dynamics simulations has been widely utilized to obtain molecular-level details of surface wettability that is commonly quantified in term of contact angle of a liquid droplet on the surface. In this work, the sensitivity of contact angle calculation at various degrees of surface hydrophilicity to the adopted potential models of water: SPC/E, TIP4P, and TIP5P, is investigated. The simulation cell consists of a water droplet on a structureless surface whose hydrophilicity is modified by introducing a scaling factor to the water-surface interaction parameter. The simulation shows that the differences in contact angle described by the potential models are systematic and become more visible with the increase of the surface hydrophilicity. An alternative method to compute a contact angle based on the height of center-of-mass of the droplet is also evaluated, and the resulting contact angles are generally larger than those determined from the liquid-gas interfacial line.

Adsorption of azacrown ethers at solid–liquid interface. Contact angle and neutron reflectivity study

2009 ◽  
Vol 256 (1) ◽  
pp. 274-279 ◽  
Author(s):  
Kamil Wojciechowski ◽  
Anna Brzozowska ◽  
Sebastien Cap ◽  
Witold Rzodkiewicz ◽  
Thomas Gutberlet
Keyword(s):  
Contact Angle ◽  
Liquid Interface ◽  
Neutron Reflectivity ◽  
Azacrown Ethers ◽  
Interface Contact ◽  
Solid Liquid Interface ◽  
Solid Liquid

Simulation of Water Flow in a Coated Nano Pore by a Molecular Dynamics

2008 ◽  
Vol 57 ◽  
pp. 73-79
Author(s):  
K. Yamamoto ◽  
T. Iwatsubo ◽  
Ken-ichi Saitoh ◽  
T. Moriuchi
Keyword(s):  
Molecular Dynamics ◽  
Contact Angle ◽  
Silica Gel ◽  
Contact Angles ◽  
Dissipation Energy ◽  
Water Flows ◽  
Piston Cylinder ◽  
Pore Length ◽  
Spherical Silica ◽  
Extension Force

This paper presents on a new damping element called the colloidal damper which is used a principle of surface extension force in nano pore. The direction acting of the surface extension force of water in hydrophobic nano pore is different in pressurization and decompressurization processes [1,2]. This principle is applied to a damping element. The nano pore is constructed by silica gel. A silica gel ball of 100-200 micrometer dia. has many nano pores of 5-20 nanometer dia. in it [3,4]. The coated spherical silica gel and water are inserted in a piston - cylinder unit in order to work as a damper. If compression and decompression forces are added to the piston - cylinder unit (damper), water flows into and moves out the nano pore under balance of pressure. A contact angle of compression formed by the hydrophobic nano pore and water is larger than that of decompression. This difference of the contact angle produces a damping energy. In this paper, behavior of water in the pore of silica gel is investigated using the molecular dynamics. Dissipation energy of the colloidal damper is concerned with the contact angles of water in the pore. So the contact angles are calculated for changing parameters, i.e. size of the pore, length of the hydrophobic material, velocity (pressure) of water flows into the pore. Then these results are compared with the experimental ones.

Ordering of ZnS Nanorods at the Air–Liquid Interface: An In Situ X-ray Scattering Study

2021 ◽  
Author(s):  
Santanu Maiti ◽  
Gouranga Manna ◽  
Sabyasachi Karmakar ◽  
Subrata Maji ◽  
Mrinmay K. Mukhopadhyay ◽  
...  
Keyword(s):  
Liquid Interface ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Air Liquid Interface ◽  
Ray Scattering

Growth of Free-Standing Polypyrrole Nanosheets at Air/Liquid Interface Using J-Aggregate of Porphyrin Derivative as in-Situ Template

2011 ◽  
Vol 44 (12) ◽  
pp. 4583-4585 ◽  
Author(s):  
Purushottam Jha ◽  
Shankar P. Koiry ◽  
Vibha Saxena ◽  
P. Veerender ◽  
Anil K. Chauhan ◽  
...  
Keyword(s):  
Liquid Interface ◽  
Free Standing ◽  
Porphyrin Derivative ◽  
Air Liquid Interface

Neutron reflectivity studies on the DNA adsorption on lipid monolayers at the air–liquid interface

2006 ◽  
Vol 385-386 ◽  
pp. 838-840 ◽  
Author(s):  
Jui-Ching Wu ◽  
Tsang-Lang Lin ◽  
U-Ser Jeng ◽  
Naoya Torikai
Keyword(s):  
Liquid Interface ◽  
Lipid Monolayers ◽  
Neutron Reflectivity ◽  
Dna Adsorption ◽  
Air Liquid Interface

Microfabrication Technologies Based on Electro-Dispensing

2011 ◽  
Author(s):  
Jacqueline Nichols ◽  
Brandon Born ◽  
Emily L. Landry ◽  
Jonathan F. Holzman
Keyword(s):  
Contact Angle ◽  
New Technologies ◽  
Polymer Processing ◽  
Contact Angles ◽  
Beam Focusing ◽  
High Contact Angle ◽  
Electromagnetic Models ◽  
On Chip ◽  
Microfabrication Technology

A microfabrication technology with real-time polymer processing control is introduced in this work. The technique is titled electro-dispensing, as it employs a metal micro-dispensing tip that is biased with a user-defined voltage. The in-situ voltage directs an electric field through the underlying dispensed polymer structure. Polymer droplets are dispensed directly onto a chip with precise (pL) volumes, and the in-situ micro-dispensing tip voltage is varied to adjust the polymer droplet morphology during the microfabrication process. The technique is carried out within a glycerol ambient filler solution, to create an initial high contact angle (160°) on the polymer microdroplets, and voltage tunability is applied to control the microdroplet shapes. Ultraviolet curing is subsequently employed to solidify the micro-spheroid structures on the desired locations across the chip. The electro-dispensing process is demonstrated in this work for numerous microdroplets, with a variety of polymer morphologies and diameters down to 150 μm. The capabilities of the electro-dispensing process are also demonstrated in this work for a specific application relating to integrated photonic circuitry. Polymer microdroplets in the past have been limited to use as lenses for vertical beam focusing (through the plane of the chip), because of their exceedingly low contact angles on solid surfaces. In this work, polymer micro-droplets are introduced for lateral beam focusing and retroreflection (above and parallel to the plane of the chip). These new technologies for on-chip optical beam dispersion management are brought about by the capabilities of electro-dispensing: the use of an ambient filler allows the dispensing process to create high-contact-angle near-spherical microdroplets; the electro-dispensing process then allows this droplet to be tuned for its specific role within the integrated photonic chip (e.g. as a spherical element for in-plane focusing or an elliptical element for in-plane retroreflection). Ray-based analyses and electromagnetic models are used to characterize the optical responses of the micro-spheroid structures, and the results are compared to experimental measurements with on-chip laser beam control.

Molecular Dynamics Simulation of Ultra-Fast Phase Transition in Water Nanofilms

2020 ◽  
Author(s):  
Malcolm Porterfield ◽  
Diana Borca-Tasciuc
Keyword(s):  
Molecular Dynamics ◽  
Contact Angle ◽  
Morse Potential ◽  
Water Film ◽  
Contact Angles ◽  
Gold Substrate ◽  
Explosive Boiling ◽  
Interaction Sites ◽  
Lennard Jones ◽  
Water Films

Abstract Molecular dynamics simulations are used to explore explosive boiling of thin water films on a gold substrate. In particular, water films of 2.5, 1.6 and 0.7 nanometer thickness were examined. Three different surface wettabilities with contact angles of 11, 47 and 110 degrees were simulated along with substrate temperatures of 400K, 600K, 800K and 1000K. The 11 degree contact angle was obtained using a Morse interaction potential between the water film and the gold substrate while the 47 and 110 degree contact angles were obtained via a Lennard-Jones potential. Evaporation was the first mode of phase change observed in all cases and explosive boiling did not occur until the substrate reached a temperature of 800K. When explosive boiling was present for all three contact angles, it was consistently shown to occur first for the surface with a 47 degree contact angle, contrary to the expectation that it would occur first on the substrate with an 11 degree contact angle. These results suggest that explosive boiling onset is strongly dependent on the particularities of the interaction potential. For instance, the Morse potential used to model the surface described by an 11 degree contact angle, is a softer potential as compared with Lennard-Jones, but has more interaction sites per molecule — two hydrogen atoms and one oxygen atom vs one oxygen atom. Thus, although the water film reaches a higher temperature with the Morse potential, explosive boiling onset is delayed as more interaction sites have to be disrupted. These results suggest that both the interaction strength and the number of atoms interacting at the interface must be considered when investigating trends of explosive boiling with surface wettability.

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